Sinking Support Posts and a Bouncy Floor: A Ladson Foundation Settlement Case Study

The homeowner in Ladson contacted us after noticing a noticeable bounce in the floor near the center of the home — the kind of soft, springy give underfoot that tells you something beneath the floor is no longer doing its job. They had lived with it for about a year. By the time we arrived, the deflection was measurable.

The Crawlspace Blueprints™ inspection revealed two wooden support posts in the center of the crawlspace that had sunk into the soil beneath them. The posts were visibly tilted — no longer plumb — and the main carrying beam they supported had deflected 1.4 inches below its original level position. A laser level confirmed the measurement. The floor joists spanning from that beam were bowing downward in the center, which is exactly what produces the bounce felt on the first floor above.

The soil beneath the posts was saturated. No vapor barrier, no moisture management of any kind. The bare soil had been absorbing and releasing moisture through multiple seasonal cycles, and the posts — sitting on small concrete pads directly on the soil surface — had gradually worked their way down as the soil softened and compressed beneath the load.

Wooden support posts in a crawlspace are only as stable as the surface they bear on. When that surface is bare, unprotected soil with no vapor management, the soil's load-bearing capacity changes with its moisture content. In the Lowcountry, where the water table is close to the surface and seasonal rain events are frequent and heavy, soil saturation is not an occasional condition — it is a recurring one.

Over time, repeated wet-dry cycles cause soil to compress and shift under point loads. The posts follow the soil down.

The 1.4-inch deflection was the cumulative result. The bounce was the symptom. The unmanaged crawlspace was the cause.Ladson · diagnostic summary

No amount of shimming the posts would have resolved the problem without first addressing the moisture condition — the soil would have continued to move.

The moisture system was installed first — always.

Structural corrections made in a wet crawlspace will not hold. The sequence is not optional. With the moisture system in place, the structural correction followed and produced a result that will stay in place.

At the 30-day follow-up, relative humidity was holding at 53% RH. The beam was stable at its corrected elevation. The homeowner confirmed the floor bounce was gone immediately after the structural correction was completed.

A floor that bounces is not a cosmetic issue — it is a structural one, and it does not self-correct. A Crawlspace Blueprints™ inspection will document the deflection, identify the cause, and give you an engineered path to correction before the problem advances further.